In general, a vehicle has a foot brake for performing a braking operation during driving and a parking brake for performing a braking operation when the vehicle is parked. The parking brake lever is generally operated by hand. Pulling the lever pulls a brake cable to carry out the braking operation.
Frequent braking operations can loosen the brake cable, causing insufficient tension, and thereby reducing the braking force. If the brake cable is loose enough, even fully pulling the parking brake lever may not perform the braking operation properly. In this circumstance, the vehicle should be repaired so that the cable length is adjusted by a repairman.
Many devices for automatically adjusting the brake cable tension have been developed.
For example, U.S. Pat. Nos. 5,272,935 and 6,382,048 disclose devices for automatically adjusting the brake cable tension. The described techniques employ elastic members such as a spring for automatically adjusting the brake cable tension. However, the structure of these devices is complex and is not easy to repair or assemble because of the large number of components.